Merge tag 'tpm-030822' of https://source.denx.de/u-boot/custodians/u-boot-tpm

[platform/kernel/u-boot.git] / drivers / mtd / spi / sf_mtd.c

diff --git a/drivers/mtd/spi/sf_mtd.c b/drivers/mtd/spi/sf_mtd.c
index 935ae4d..071b25a 100644 (file)
--- a/drivers/mtd/spi/sf_mtd.c
+++ b/drivers/mtd/spi/sf_mtd.c
@@ -1,7 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2012-2014 Daniel Schwierzeck, daniel.schwierzeck@gmail.com
- *
- * SPDX-License-Identifier:    GPL-2.0+
  */
 
 #include <common.h>
@@ -10,7 +9,22 @@
 #include <linux/mtd/mtd.h>
 #include <spi_flash.h>
 
+#if CONFIG_IS_ENABLED(DM_SPI_FLASH)
+
+int spi_flash_mtd_register(struct spi_flash *flash)
+{
+       return add_mtd_device(&flash->mtd);
+}
+
+void spi_flash_mtd_unregister(struct spi_flash *flash)
+{
+       del_mtd_device(&flash->mtd);
+}
+
+#else /* !CONFIG_IS_ENABLED(DM_SPI_FLASH) */
+
 static struct mtd_info sf_mtd_info;
+static bool sf_mtd_registered;
 static char sf_mtd_name[8];
 
 static int spi_flash_mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
@@ -18,6 +32,9 @@ static int spi_flash_mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
        struct spi_flash *flash = mtd->priv;
        int err;
 
+       if (!flash)
+               return -ENODEV;
+
        instr->state = MTD_ERASING;
 
        err = spi_flash_erase(flash, instr->addr, instr->len);
@@ -28,7 +45,6 @@ static int spi_flash_mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
        }
 
        instr->state = MTD_ERASE_DONE;
-       mtd_erase_callback(instr);
 
        return 0;
 }
@@ -39,6 +55,9 @@ static int spi_flash_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
        struct spi_flash *flash = mtd->priv;
        int err;
 
+       if (!flash)
+               return -ENODEV;
+
        err = spi_flash_read(flash, from, len, buf);
        if (!err)
                *retlen = len;
@@ -52,6 +71,9 @@ static int spi_flash_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
        struct spi_flash *flash = mtd->priv;
        int err;
 
+       if (!flash)
+               return -ENODEV;
+
        err = spi_flash_write(flash, to, len, buf);
        if (!err)
                *retlen = len;
@@ -74,6 +96,17 @@ static int spi_flash_mtd_number(void)
 
 int spi_flash_mtd_register(struct spi_flash *flash)
 {
+       int ret;
+
+       if (sf_mtd_registered) {
+               ret = del_mtd_device(&sf_mtd_info);
+               if (ret)
+                       return ret;
+
+               sf_mtd_registered = false;
+       }
+
+       sf_mtd_registered = false;
        memset(&sf_mtd_info, 0, sizeof(sf_mtd_info));
        sprintf(sf_mtd_name, "nor%d", spi_flash_mtd_number());
 
@@ -90,15 +123,41 @@ int spi_flash_mtd_register(struct spi_flash *flash)
 
        sf_mtd_info.size = flash->size;
        sf_mtd_info.priv = flash;
+       sf_mtd_info.dev = flash->dev;
 
        /* Only uniform flash devices for now */
        sf_mtd_info.numeraseregions = 0;
        sf_mtd_info.erasesize = flash->sector_size;
 
-       return add_mtd_device(&sf_mtd_info);
+       ret = add_mtd_device(&sf_mtd_info);
+       if (!ret)
+               sf_mtd_registered = true;
+
+       return ret;
 }
 
-void spi_flash_mtd_unregister(void)
+void spi_flash_mtd_unregister(struct spi_flash *flash)
 {
-       del_mtd_device(&sf_mtd_info);
+       int ret;
+
+       if (!sf_mtd_registered)
+               return;
+
+       ret = del_mtd_device(&sf_mtd_info);
+       if (!ret) {
+               sf_mtd_registered = false;
+               return;
+       }
+
+       /*
+        * Setting mtd->priv to NULL is the best we can do. Thanks to that,
+        * the MTD layer can still call mtd hooks without risking a
+        * use-after-free bug. Still, things should be fixed to prevent the
+        * spi_flash object from being destroyed when del_mtd_device() fails.
+        */
+       sf_mtd_info.priv = NULL;
+       printf("Failed to unregister MTD %s and the spi_flash object is going away: you're in deep trouble!",
+              sf_mtd_info.name);
 }
+
+#endif /* !CONFIG_IS_ENABLED(DM_SPI_FLASH) */